Magnetic tunnel junctions store data based on an orientation of a free (switchable) magnetic layer(s) relative to a fixed (reference) magnetic layer(s) that are separated from one another by a tunnel barrier. Having the free magnetic layer oriented parallel to the fixed magnetic layer represents one data value, while having the free magnetic layer oriented anti-parallel to the fixed magnetic layer represents another data value, for instance a logic “1” and a logic “0,” or vice versa. The orientation of the free magnetic layer can be switched between these two data states.
Stray on-chip magnetic fields can randomly switch the electron spin in magnetic tunnel junctions or skew the probability of switching. Some examples of sources of these stray on-chip magnetic fields include on-chip inductors and cobalt (Co) liners used for back-end-of-line (BEOL) metallization. Such factors are undesirable as they affect the switching accuracy of magnetic tunnel junction devices.
Therefore, improved magnetic tunnel junction devices that are resistant to stray on-chip magnetic fields would be desirable.